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SCIENCE FINAL 7TH GRADE :O

Flashcards for science final in 2012, June 13
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Why are solution poullutants harder to remove from water than mixture pollutants?
The solution pollutants are bonded with the water
Why is water essential for life?
Water is essential for life because all cells need water to survive. Water transports nutrients and wastes into/out of cells.
Why is water so hard to clean?
Water is so hard to clean because pollutants can form solutions as they dissolve in water.
Why are septic systems important?
To hold wastewater until it can be pumped out
What is one of the limitations of a septic system that a wastewater treatment system doesn't have?
Septic systems take much longer to clean water than wastewater treatment systems
Which of the following is a job of the sewage treatment plant?
Clean water for an entire community
A recent law has been passed in Connecticut that limits the amount of fertilizer homeowners are allowed to use on their yards. What benefit will this have on Connecticut's watersheds?
Reduce run-off pollutants
Pollution is found in the Long Island Sound flowing from Connecticut River. Where might the pollution have originated from?
Connecticut, Massachusetts, New Hampshire, or Vermont
When trying to freeze, dehydrate, or pickle food, what are we trying to do?
Stop bacteria from growing
When we try to preserve food with freezing, pickling, and dehydrating, what are we changing around the food?
Favorable environment
Pickling is a food preservation technique that
preserves food by using a salt and an acid to inhibit bacterial growth
Water molecules in potato cells are stored in what organelle?
Vacuole
The main difference between an animal cell and a plant cell is that...
an animal cell must bring in glucose while a plant cell may make its own
Name two organelles and describe their functions.
Nucleus-directs cell functions
Chromosomes-store genetic info
Cell membrane-controls what goes in & out of the cells
cytoplasm-jelly-like substance that supports the cell
Mitochondria-produces energy; powerhouse
Name two additional cell parts found in plants, but not in animals.
Cell wall and chloroplast
Describe the function of one structure found in plants and not animals.
cell wall-supports plant cell
chloroplasts-convert energy from the sun into energy the cell can use
What would happen if one of a cell's organelles were missing? Pick an organelle to remove and describe what might happen to the cell.
If a mitochondria was missing from a cell, the cell would loose all its energy and not be able to function and die.
The instructions that determine coat (dog) color are stored in the
chromosomes of every cell
What are two abiotic factors that would affect photosynthesis?
Carbon dioxide and water
Why is it important for a plant to get plenty of sunlight to stay healthy?
The sunlight is used to power the cell to make sugar.
Oxygen and sugar are the products of
photosynthesis
What is the difference between photosynthesis and respiration?
Photosynthesis makes glucose and respiration uses glucose
The process by which water moves across a selectively permeable membrane is:
osmosis
If a blood cell is placed in a liquid with a very high salt concentration, water molecules will:
leave the cell
Normal human cells contain 46 chromatids each. How many chromatids are there in a sex-cell after meiosis?
23 (46/2=23)
What is the difference between sexual reproduction (meiosis) and asexual reproduction (mitosis)?
asexual reproduction (mitosis) produces copies only
What is the difference between a cell created at the end of meiosis and a cell created at the end of mitosis?
Meiosis produces cells that have one gene per trait while mitosis cells have two genes per trait
Black fur is dominant to white fur. Two black mice are mated. The offspring are both black and white mice. Explain how this can happen. You must specify the genotype of the parent mice.
The black mice could be hybrids (Bb) When they mate there is a possibility that the offspring would be (bb) or white.
An organism has the genes Bb. Circle which of the following parents could have produced him.
BbxBB
If someone is heterozygous, what is the chance that the person will pass on the dominant gene?
50%
Egg and sperm are made:
by meiosis
The function of the reproductive system is:
to continue a species
Identify the levels of organization from smallest to largest
cells, tissues, organs, organ systems
Why must your heart rate increase during times of exercise?
The body needs more oxygen and the heart needs to speed up to meet the need.
How do the digestive, respiratory, and circulatory systems help the body maintain homeostasis?
They allow the body to bring in and move materials as needed.
Why do muscles need to work in pairs?
Muscles can only pull
Which body system's primary function is the continuation of the species?
reproductive
The terms gas exchange, diaphragm, and inhale are most closely associated with which system in the human body?
Respiratory
Which two body systems work together to transport oxygen to the cells?
Respiratory and circulatory